Drive mechanism for concrete mixers



C. l. BOHMER `DRIVE MECHANIVSM FOR CONCRETE MIXERS Feb. .18, 1947.

Filed July 27, 1944 Patented Feb. 18, 1947 STATES Par DRIVE, MECISM FOR CONCRETE MIXERS Ciarence I, Rohmer, Columbus, Ohio, assigner to The Jaeger Machine Company, Columbus, Ohio, a corporation of Ohio Application `li'uly 27, 1944, Serial No. 546,820

(o1. 25a-177i 4 Claims.

This invention relates to concrete mixers, having particular reference to an improved drive mechanism for imparting rotating power to the agitating drums of such mixers. While my invention is not so limited, it has practical application to concrete-mixing apparatus of the type mounted on automotive vehicles for mixing the concrete-forming materials during transit or other operational use of the vehicles.

It is an object of the invention to provide such a vehicle mounted concrete mixer with a rotatable mixing drum which is driven by an engine independent of the vehicles propelling engine and disposed at the lower end of the drum on the vehicle frame.

It is another object to provide the mixeroperating engine with an improved transmission for imparting controlled rotary motion to the mixing drum, and wherein the engine, transmission and rear end of the drum is housed in a vehicle-carried casing or shell which protects the mechanism enclosed thereby, as well as improving the external appearance of the apparatus.

It is a further object of the invention to provide a propelled concrete mixer with a compact and structurally simplified, engine driven, powertransmitting means for rotating the mixing drum and wherein the engine and power-transmitting means are disposed within the transverse measurements of the vehicle, so that parts projecting laterally from the sides of the vehicle are eliminated, whereby to make it feasible to enclose such parts in a protective casing.

Still, a further object is to provide a simple,

compact and eicient drive mechanism for the f.

rotary drum of a concrete mixer, and wherein one end of the drum is formed with an internal gear which is rotated by a spur pinion mounted on an engine-driven shaft.

For a further understanding of the invention, reference is to be had to the following description and the accompanying drawing, wherein:

Fig. 1 is a front elevational View of the improved drive mechanism for the rotary drum of a vehicle mounted concrete mixer, a portion of the casing surrounding the drive mechanism being broken away and shown in section to disclose internal structure;

Fig. 2 is a detail side elevational view, partly in vertical section, ci said drive mechanism;

Fig. 3 is a horizontal sectional View taken on The bed is adapted to be disposed at an acute angle with respect to the horizontal, having an elevated rear end in which the mix-forming materials are received and discharged. The forward or lower end of the drum is closed by the wall 'l and the interior of the drum is provided with the usual mix-agitating and conveying blades, not shown. The rear wall 'l in the longitudinal axis of the drum is provided with a supporting stud or trunnion 8, which is received in an antifriction, thrust-absorbing bearing 9, and, at its rear end, the drum is rotatably supported in any conventional manner.

Mounted on the bed 5 at the iront of the drum 6, and extending transversely across the bed, is a drum-operating internal combustion engine l2, with which is unitarily associated a standard change-speed transmission embodying a casing i3 and a manually operated gear-changing lever i4. The rear of the engine l2 and the transmission casing i3 is supported on a second gear casing l5y stationarily mounted in connection with the bed 5, and below the casing l5 watercontaining tanks i5 are arranged to form a part of the bed and on which the engine and transmissions are mounted. This arrangement is advantageous in that' it saves considerable vertical space due to the elimination of structural members for carrying the engine and transmission, reduces the height of the apparatus and provides for a more compact grouping of necessary'elements.

Within the transmission casing l3,`there is provided an engine driven shaft H, which carries a spur pinion I8. This pinion meshes with the teeth of a larger idler gear i9, rotatably supported as at 20 within the casing i3. The gear i9 meshes with a gear 2| mounted on a shaft 22 arranged within the casing l5. Rotatable with the gear 2l is a pinion 23, which meshes with a gear 24 secured to asecond shaft 25, the latter being journaled as at 25 within the vcasing I5 in parallel relationship to the shaft 22.

Rotatable with the Vshaft 25 is a beveled toothed pinion 2l", which meshes with a beveled gear 28. f

ternally toothed bull gear 32, the latter being fixed to the rear wall of the drum 6.

By this arrangement, a compact drive mechanism is provided for rotating the mixing, drum, the water-receiving tanks IG and the gear casing I5 being disposed below the horizontal plane of the engine l2 and its transmission i3. However, all parts are arranged within the confines of the standardv width measurementsA of the bed 5. By the use of the internal gear drive for the mixing drum, I obtain the advantages of smaller diameter, better alignment andthe elimination-- of the ilexing stresses in undesirable directions; The principal advantage of the internal gear lies in the fact that for a given reduction, the diameter can be lmuch smaller than conventional drives.

The shaft il drives a coupling or clutch 33A i which is connected to a pump shaft 34 of a pump shaft I?, a direct drive is thusprovided to the pump, eliminating the need for belts or chains hitherto used in this capacity.

BS reason of the compactdrive mechanism thus provided, the front end of thedrum 9, the

engine i2 and associated' parts driven thereby may be housedwithin an externally disposed protective casing 39; This casing constitutes a symmetrical continuation of the upper and rearportion of the drum-S, and whileit' servesto protect the mechanisms` encased' thereby, it also contributed in improving the external'appearance of the apparatus, producing a so-called streamline eiect; The casing may be provided with a hinged door 4E' which providesconvenient access to the compartment. IH in which the engine, transmission, andv pump mechanisms are mounted. Also, cooperative with the casing 39 are stationary side panels 42; by which the external appearance of the apparatusisimproved;

By so combining and compacting the drive mechanism, the present invention'providessuch an orderly" grouping of the various partsfY of said mechanism as to enable the sameA tobeA disposed entirely within the marginal confines of the bed ii on which' theyare mounted; avoidihgexpressly the use of partsv which project laterallyv beyond the sides of the apparatus and which aref not only unsightly but which are apt tov form travel hazards;

Having thus described myinvention, I claim:

1. In portable concreteh mixing apparatus, a vehicle bed, a liquid-receiving tank forming a stationary componentV part of said'bed and disposed in al horizontal planeet the rear endthereof, an internal combustionengine arranged transversely of said bed aboven said tank, a pri-mary transmission driven by said engine disposed in longitudinal alignment therewith, a secondary transmission mounted on said tank and disposed below said primary transmission in power transmitting relationship with the latter, a rotatable mixing drum mounted on said' bed with its principal axis extending longitudinallythereof, said drum having a closed forward end, an internal gear fixed to theforwardend of said drum in concentric relation withv its principal axis', and a pinion driven by said secondary transmission in mesh with the teeth of said internal gear.

2. In portable' concrete mixing apparatus, a vehicle bed, a rotatable mixing drum mounted on said bed with itsprincipal axis extending longitudinally of the bed, saiddrum having: af closed forward end, an internal gear fixed toA the-closed end of saidv drumin'concentric relationwith. its

t principal axis, an internal combustion engine supported vaboveV said bed atthe front'of said drum, the principal axis of the engine extending transversely of said bed, a primary transmission arranged in alignment with said engine, a secondary transmission supported by said bed below said primary transmission and in power-transferring relationship therewith, a pinion driven by said secondary transmisson arranged in mesh with the internal gear of said drum, and a liquid-receiving tank structure forming a stationary component part of said bed and extending transversely thereof below said engine and transmissions.

3. In portable concreteY mixing apparatus, a vehicle bed; a rotatable mixing drum mountedon said bed with itsprincipal axis extending longitudinally of the bedsaid drum having; a' closed end, an internal gear iixed to the closed end of said iii-concentric relation with its principalaxis, an internal combustion engine supported abo've'said bed'at the'rear of said' drum, the 'prin'- cipal axis of the engineextending',transversely'of" said bed, a primary transmission arranged in alignment with said engine, a secondary transmission supported by said bed below said primary transmission and in power-transferring relation"- ship therewith, aA pinion driven by'said secondary' transmission arranged in mesh withthe internalgear of said drum, a water tank structure forming anY integral part of said bed and extending transversely thereof below said engine and'trans'- missions, a pump arranged in alignment with-said' primary transmission and driven thereby, and? a 4 conduit extending from said tank to the inlet side of said pump.

4. In portable concrete mixing apparatus, a

vehicle bed, a liquid-holding tank forming-1a' stationary component part of said bed and extending transversely thereof'in a horizontal plane; an internal combustion engine arranged transverselyoi said bed above said tank, a primary transmission driven by said engine disposed-in longitudinal alignment' therewith, a secondaryl transmission mounted on said tank' andr disposed below said primary transmission in power-transmittingz relationship with the latter, av rotatable mixing drum mounted on said bed with its-principalY axis extending longitudinally thereof, said drum" having a closed end, a gear ring xed tothe closed end of sai-d drum in concentric relation withits principal axis, and a pinion driven by saidsecondary transmission in lneshl with the teeth of said gear ring.

CLARENCE-I. BOHMER;

REFERENCES CITED The following references are' of' record in the leof this patent:

UNITED STATES PATENTS British May 26,l 1930 

